NEW YORK (Reuters Health) - Simply thinking about something personally meaningful can ease some of the physiological effects of stress, a new study suggests.

In an experiment with college students asked to perform a stressful task, researchers found that those who first reflected on some important personal values -- whatever they were -- showed lower levels of a stress-hormone while they were under pressure.

The findings are the first to show that such self-reflection can change the hormonal response to stress, according to lead study author J. David Creswell of the University of California Los Angeles.

"Reflecting on personal values, even something like your abilities as a good father, can act as a buffer against stress," Creswell said in an interview.

He and his colleagues report the results in the November issue of the journal Psychological Science.

The study, according to Creswell, grew out of the body of research on "self-affirmation," whereby people essentially remind themselves that they are basically good and talented. People who draw on this idea may, for example, be less likely to blame themselves after something goes wrong.

For their experiment, Creswell and his colleagues had 80 college students go through the stressful task of explaining why they were a good candidate for a university job to a pair of stern interviewers.

Beforehand, about half of the students answered questions that caused them to think about an area of life that they had earlier identified as important to them -- such as religion, social issues or politics. This was a "subtle" way to lead them into reflecting on their personal values, Creswell noted.

The rest of the students answered questions on issues that were not personally meaningful to them.

Before and after the stressful task, the researchers took saliva samples from the students to measure levels of the hormone cortisol, which tend to spike in response to stress.

Overall, the study found, students who'd reflected on their personal values showed less of a cortisol response to the stressful situation.

It's not clear what health benefits might be gained from such a muted cortisol response. But studies have linked chronic stress in general to a number of ill health effects, such as high blood pressure and heart disease. There is also evidence that emotional stress can precipitate a heart attack in people with existing heart disease, perhaps partially via stress hormones.

Creswell and his colleagues are currently studying how reflection on personal values affects people with chronic diseases.

Such self-reflection, Creswell noted, stands as a potentially powerful stress buffer, since it's something people can readily draw upon in their everyday lives.